... That is like saying, can I open a picture in paint that is in my own format that I will not tell you the specification of... Take another copy, save it as something standard such as .img or .iso and it should work easily and you should have no problems creating another copy from the image... (well almost... I know not that accurate, but hopefully you understand where I am coming from!)
– William HilsumAug 22 '09 at 20:39

I need to use ddrescue. It is not my own format, it is raw CDFS file system.
– Isaac WallerAug 22 '09 at 20:42

I have amended my answer based on the additional information.
– BinaryMisfitAug 22 '09 at 20:54

Ugh, first off: CDs do not normally have partition tables. Second, a raw dump of the bytes on a CD-ROM is what most people call an ISO file.
– derobertAug 23 '09 at 9:25

6 Answers
6

When reading a CD, /dev/disk1 will access the entire 2352 bytes of each block. This is useful for reading an audio CD. It is sometimes called a raw image, or a CloneCD image.

On a MODE 1 CD-ROM, 2048 bytes of each 2352-byte block is used for data and most of the rest is used for error correction codes, because the integrity of the data is so important. With file system data, it is not possible to just ignore an erroneous sample like on an audio CD. Use /dev/disk1s0 to read the 2048-byte blocks, using the error correction codes to detect and correct any errors within each block. An ISO 9660 file system image is made up of these 2048-byte blocks, and you will be able to mount the resulting image directly.

If the CD-ROM contains a file system then there is not much point in capturing it in the raw format, since the error correction codes are redundant and will be recreated when you record the ISO image to another CD-ROM. However, if you already have the raw image and want to strip off the extra information, there is a program called ccd2iso which will do that.

It's not a IMG file - I just gave it that extension.
– Isaac WallerAug 22 '09 at 20:25

so what extention is it! that is quite important :S
– William HilsumAug 22 '09 at 20:27

1

I agree that would be extremely useful information, as disk mounting is natively support on the Mac and therefore creating an image in an unsupported format would be a reason it won't mount?
– BinaryMisfitAug 22 '09 at 20:32

On your Mac OS X command line type: file <name of file here> and get back to us!
– X-IstenceAug 22 '09 at 20:51

1

@Diago: Your dd line does the exact same thing as cp filename.img file.iso, except is maybe a little slower due to the weird block size.
– derobertAug 23 '09 at 9:23

I know it is late. But I saw this question and got the answer from your comments. kinokijuf said its a raw image. Then derobert mentioned that a raw image is what is usually called an iso image. So then change the name or extension of the file to something like > image.iso